Cement and lime burning



April 26, 1927.

l G. E. HEYL CEMENT AND LIMEi BURNING Filed March 4. 1926 HTTORNEYS,.

Patented Apr. 26, 1927.

UNITED STATES GEDRGE EDWARD HEYL, 0F WESTMINSTER, LONDON, ENGLAND.

CEIENT AND LIME BURNING.

Application led lai-(m4, 1928, Serial No. 92,271, and in Canada March 5, 1926.

rlllhis invention relates to'cement burning and is also applicable to lime burning.

Various proposals `have already been made for avoiding the use of expensive rotary kilns for cement burning, by blowing the powdered Portland cement-forming mixture mixed with a powdered fuel into a chamber wherein the powdered fuel blast burns as a flaming jet maintaining a vitrifying temperature. It has also been proposed to insulate suliicient lime with a blast of powdered coal (mixed or not with the coal) into a kiln in whichca cement forming mixture is being calcined by the ilamin -coal blast, tor the purpose of providing ad itional lime to combine with the calcareous a'sh from the coal to form cement similar to and thus not contaminating the cementwhich is being burnt in thekiln.

Now it cement-formin material is blown into a vitrifying cham er mixed with a powdered fuel, the particles of cement-forming ingredients are separated by fuel particles, whereas for promoting the combination or' the ingredients mutual contact thereof should be intimate. Also, if as hasbeen proposed, the cement-forming material is blown concentrically with a surrounding blast flame, the exposure of the cement-forming material to the llame is incomplete.

Hence, according to the invention, a mixture of' Portland cement-forming materials in dry finely powdered form, blown as a jet .Yin a combustion chamber into a`1'egion wherein a vitrifying or calcining temperature is maintained by a flaming jet of combustible separate from the jet oi Portland cement-forming mixture, is caused to encounter tlie flaming jet. i

The aming jet which the powdered cement-forming material to be vitrilied, blown by a jet of compressed `air from a nozzle into the chamber, encounters, may be aflaming blast of combustible'gas, oil oneven powdered solid combustible conveyed by ap vjet of compressed air from another nozzle.

rlhe vitrifying `temperature is as usual about lOO-ltillllc C. f

rlhe above described method is also applicable to lime burning, chalk or limestone vastly in excess` of the ash-content, if any,

oit the fuel, being blown into the hi hutem perature region instead ofcementorming material.

A plant for carrying out the invention is diagrammatically illustrated on the accompanying drawing, in which Fig. l is a sectional plan, and Fig. 2 is a transverse section on the line `2---2 of Fig. 1.

The burners a are arranged at opposite sides of the chamber b, thc burners on the one side being opposite those on the other lside so that their blast flames mutually encounter.

Similarly at one end of the chamber b, a

i jet of powdered cement-forming material,

is blown into the chamber b from a nozzle by an air jet from a nozzle g, the pow- 'lered material being fed from a hopper I1..

The jet of cement-forming material projected from the nozzle f transversely encounters and penetrates into the flaming blasts of fuel, from the burner nozzle a, and, the temperature of the flames being appro- `priately adjusted, is vitrified therein.

When the plant is used for burning lime, obviously limestone or chalk is substituted for powdered cement-forming material in the hopper k, and the blast flames from the nobble a are adjusted to give a flame of a suitable tvemperature for reducing the limestone or chalk to lime.

Part of the cloud of cement or lime, as

chamber b, but some tends to be carried by the products of combustion out of the charnber. To give the powdered material opportunity to settle and to promote such settlement a lateral flue i is branched od from the chamber b opposite the nozzle f. This ue t' is divided by baflles j at intervals into a seriesr of chambers in which the wdered material is encoura ed to settle by t e checks imposed by the ba es to the dow of the teenaloustion gases and also by reason ofthe ex'- tended path thereby provided for such gases.

The settling flue v, conveniently progressively converges transversely in order to -mainta`in the rate of low of the due gases despite the progressive deposit of material andthe reduction of volume due to cooling. The settling chamber may however be other- .the case may be, settles in the combustion wise arranged to provide by the reduction of volume of the gases or positively by an enlargement ot the section of the due encouragement to settling of the material by a reduction in the velocity of dow of 'the gases.

The material which settles on the tioor of the subdivided liue i and on the floor of the combustion chamber adjacent to the inlet of this liuc, is removed by a screw conveyor ZJ, and delivered at an outlet Z in the floor at theend of the due t.

The spindle of the screw conveyor 7c is bollow andn traversed by cooling water..

From the liuc z the combustion gases pass to an uptalre or other outlet by a lateral flue jl.

The walls, ioor and roofot the chamber b and ot the flue z' are hollow and are traversed bv wafer, to cool the deposited mate rial. The water jacket m thus constituted acts as a boiler for the recovery and utilization of heat. lhe llames j may likewise be hollow and traversed by water for the cooling purposes. The yheat thus abstracted from the material may be utilized for heating and to supply hot air to the nozzles, for predrying material to be treated and for supplying steam or hot Water for other puroses. -P'When solid combustibles are employed they are so selected that the ash-content is such as not materialy to alter the adjustment of the mixture.

Lacasse Claims:

l. it. method of burning calcareous material consisting in blowing in a plurality of successive planes opposing jets of combustible liaming at a vitrifying temperature, and blowing a separate jet of powdered calcareous material transversely, successively to encounter said flaming jets.

2. A method of burning calcareous material7 ,consisting in blowing in a plurality of successive planes opposing jets of powdered solid combustible naming at a vitriiying temperature, and blowing a separate jet of powdered calcareous material transversely successively to encounter said flaming jets.

3. A method of burning cement, consisti ing in blowing in a plurality of successive planes opposing jets of combustible lan'iing at a vitriying temperature, and blowing a separate jet of a mixture of dry powdered Portland cement-:Horming'materials trans- 

